222 
AUG. F. FOERSTE 
limited by a more or less lunate outline which becomes con- 
spicuous on cross-illumination. 
The hypostoma closely resembles that of Remopleurides striatu- 
lus Walcott (Cincinnati Quarterly Journal of Science, II, 1875, 
p. 347) in general form, and is 6 mm. in length. 
From localities 2 and 4 in the Sanders Branch section, in the 
Kimmswick limestone. 
In Remopleurides striatulus Walcott (plate 41, figs. 18 A, B, C, 
of this Bulletin), from the Trenton of New York, the smooth 
lines indicating the glabellar furrows are indistinct, those corre- 
sponding to the anterior and posterior pairs being extremely 
obscure. The general curvature of the glabella is very moderate 
except at its anterior margin, where the frontal lobe curves 
more strongly downward. 
Compared with Remopleurides striatulus^ the Ralls County 
specimens have much more distinct indications of the glabellar 
furrows; the frontal lobe curves downward more strongly and 
for a greater distance; and the general aspect of the glabella is 
somewhat narrower and less flattened. 
In Remopleurides linguatus Ruedemann, from the basal Tren- 
ton (Rysedorph) of New York, the anterior extension of the 
frontal lobe is much narrower and more prolonged. 
In Remopleurides tumidus Ruedemann, from the same horizon 
and locality, the glabella is relatively broader, the anterior exten- 
sion of the frontal lobe is shorter, and it is bounded laterally by 
more converging facial sutures; moreover, the convexity of the 
cranidium from front to rear is greater. 
43. Bathyurus spiniger Hall 
Plate XXII, fig. 20 
Cranidium with posterior margin of neck ring dentate on 
each side of the median spine. Those parts of the cranidium 
which are immediately posterior to the palpebral lobes are 
indistinctly preserved. From the top of the Plattin limestone, 
in the city quarry, 1 mile southeast of New London, in Ralls 
county. 
